The disclosures herein relate generally to computer systems and more particularly to a system for providing a video signal to a display device in a scalable platform.
Computer systems with scalable video solutions are becoming more popular. These platforms offer the choice between a low cost, low performance video controller integrated in the chipset on the motherboard or the addition of a higher cost, higher performance video controller, such as a video controller on card that couples to an AGP (Accelerated Graphics Port) slot, plugged into the system. The integrated video controller uses a display connector on the motherboard, and the additional video controller uses a display connector on its card. Where the platform includes the additional video controller, a user may not know which connector to use to plug in a display device.
FIG. 1 is a prior art embodiment of a computer system 100 that illustrates this scenario. In FIG. 1, a processor 110 is coupled to a chipset 120 that includes a bus-input/output (I/O) controller 122, a memory controller 124, and an integrated video controller 126. A system memory 130 is coupled to chipset 120. An optional video controller 140 and a memory 142 are also included in computer system 100. Video controller 140 is coupled to chipset 120 using a port 144 such as an AGP port.
In FIG. 1, video controller 126 provides its output signals to a display device that couples to a connector 222. Likewise, video controller 140 provides its output signals to a display device that couples to a connector 214. As indicated by arrows 162 and 164, a display device 160 may be coupled to either connector 222 or connector 214 to receive output signals from either video controller 126 or video controller 140, respectively.
FIG. 2 is a diagram illustrating a prior art embodiment of a chassis 200 of the computer system 100. In FIG. 2, chassis 200 includes various connectors 212, 214, 222, 224, 226, and 228 that may be used to connect various devices to computer system 100. Chassis 200 also includes card slots 202, 204, 206, and 208 to provide access to connectors on cards such as connectors 212 and 214. As shown in FIG. 2, connectors 222 and 214 are identical such that each is capable of connecting to display device 160. As shown in FIG. 1, connectors 222 and 214 are coupled to video controllers 126 and 140, respectively. A user may not know whether to connect display device 160 to connector 222 or connector 214. It may be possible to detect to which connector the display is attached and operate through that video controller, but the user might not be attached to the higher performance controller and not receive the improvements that were purchased.
It would be desirable to for a user to know which connector to use to plug in a display device. Therefore, what is needed is a system for providing a video signal to a display device in a scalable platform.